Interest in the manufacture of imitation products to enhance the realistic look of economical metal zero-clearance, gas fireplaces is increasing due to the shift away from the traditional masonry fireplaces, because of cost and consumers' environmental concerns. Zero-clearance fireplace manufacturers usually do not make these imitation products in-house because of the specialized processes and to eliminate the contamination that can harm metal production machinery.
One conventional, albeit dusty and contaminating, method of producing low cost imitation refractory products is to mix the concrete, sand, aggregate, color, and water and to pour the blend into rubberized molds to set. The resulting product is a very heavy and dense composition that is subject to easy breakage and is expensive to transport to the end user. Another disadvantage to this concrete-type product is that when exposed to the heat and flames of gaseous fuels, they emit no glow and little radiant heat. This results in the unwanted buildup of carbon on their surface. A further drawback is that unless these products are evenly weight supported, they will crack and disintegrate under stressful burning conditions.
Another conventional method of producing imitation refractory fireplace products is the more complex, hollow ceramic process of molding clay, drying, then firing the same to produce a bisque. A desired glazing compound is then surface applied, dried, and refired to bake. This is an expensive and time consuming operation which requires two firings and two drying steps. The result produces lightweight products that will glow when set over a bar or ribbon type gaseous burner, but the porcelain-like ware is extremely fragile to transport. Another disadvantage is their limited use as they cannot be placed on popular fireplace sand pans because they will absorb the gaseous fumes and under heat, explode.
A third conventional way to produce imitation refractory fireplace products is the vacuum extraction method, which requires custom-made machinery and molding processes to form a fibre composition product. After drying, external stiffening agents must be applied for the product to maintain a rigid shape, and colors applied thereafter. While this product is lightweight, glows, and can be utilized on sand pan fireplaces, it flakes and crushes easily when transported. As the fibrous core remains soft and pliable, under humid conditions, it will absorb moisture which accelerates disintegration.
It is therefore the general object of the present invention to provide an improved material and method for producing refractory imitation firewood, coals, brick fascia boards and like objects which will obviate the above mentioned disadvantages, yet provide the desired advantages, namely a product that possesses solid mass, is lightweight, does not disintegrate and produces a red ember glow over fire with a high degree of radiant heat capable of repelling carbon buildup.
Another object of the present invention is to enable the use of rubberized molding methods which is the least costly of the foregoing processes while providing the best aesthetic definition.
Another object of the present invention is to employ inexpensive materials that are readily available and will result in lower end product cost.
Another object of the present invention is to utilize a simple process that is consistently repeatable and can be accomplished in-house without harmful effects to a manufacturer's other machinery operations and afford a substantial savings over outside suppliers' finished products.
Another object of the present invention is to provide a product that is lighter than concrete, is resistant to damage when transported, will not flake or crush, is moisture resistant, and possesses solid colour throughout its texture.